Sound of pressure release... and glow plugs

[stefan442]

Whilst finding a problem with my bongo not starting i had the glow plugs out and was generally having a look around. I found the problem to be the glow plug relay, ordered one from the bongo shop which was delivered very swiftly indeed.

Anyway, i put her all back together as i took her apart and she starts and all that jazz. But a couple of things to note, number 1 was the valve cover had two bolts that were very loose so i nipped them up. Not too much. And the second thing is i noticed my glow plugs are 101mm long, but when i took them out originally i noticed they weren't bolted all the way in, about 1cm of thread showing. I have put them back in as they came out so as not too damage the insides.

Around one of the glow plugs i get a bit of bubbling of a fluid which i assume is diesel... ?

And i also noticed when i turn the bongo off and then just turn the key back on to heat the plugs i get a sound of air under pressure being released, also at about 15 seconds into the youtube clip below there seems to be a whistling sound.

Recommend i change the valve cover gasket? As i haven't got a clue when it was done last, plus its only 20£? And will i do any damage driving her around like this for a week or so?

http://youtu.be/kPNcale8lAw

Thanks,

Stefan!


I could go to a garage and spend a bit of money but i like to learn about it and try to fix it myself.

Quick edit, can i buy a bracket for my fuel pipes anywhere?

[nerald]

Are there not two different lengths of glow plug available? Maybe yours should be the shorter length and someone has made do with the longer plugs. This could be the cause of pressure release as the plugs are not fully sealing?

[stefan442]

Are there not two different lengths of glow plug available? Maybe yours should be the shorter length and someone has made do with the longer plugs. This could be the cause of pressure release as the plugs are not fully sealing?

Yea the other lot are 83mm...... and i could bolt them right down. Id assume...

[Simon Jones]

The only difference in length is outside the cylinder head, so has no affect on functionality or ability to seal. It's possible the threads in the head have been damaged by a previous owner so maybe you're not getting such a good seal.

[francophile1947]

No, you can't screw them in further - it's only the tops that are longer on the 102mm plugs.

[stefan442]

Maybe ill give them a tweak... just didnt want to be too heavy handed. Thanks for replies!

[Northern Bongolow]

did you lube them when fitting ??. then tighten them to the required torque setting. if its still leaking then you may try another little nip as its common for them to leak, but you may risk snapping it so take care.
if the leak is slight it may seal itself when the carbon builds up but yours sounds more than this.

[Velocette]

did you lube them when fitting ??. then tighten them to the required torque setting. if its still leaking then you may try another little nip as its common for them to leak, but you may risk snapping it so take care.
if the leak is slight it may seal itself when the carbon builds up but yours sounds more than this.

If a plug has been run in a cylinder without being fully tightened, you are going to have a build up of carbon in the unused portions of the thread both in the head and on the plug. You can take the plug out and clean it with a wire brush but for the head you need a tap of some sort. Tightening the plug up without clearing the threads could cause it to seize or even strip the threads.

I have sometimes made a single use tap out of an old plug with hacksaw cuts in it and saved a motorbike head or two in my time. I must admit I have had nothing to do with glow plugs but the principle is the same. If you are in any doubt at all get a mechanic to clean the threads out for you.